He calculates couples on average wages saw their disposable income after housing costs and taxes rise 21%, or £3,600, to £16,182 between 1997 and 2002. But since then this has fallen by 6%, or £951, to £15,231.

This is partly because the tax burden has been steadily rising, increasing by a total of £7,800 per household since Labour took power.

This is expected to continue. According to the Institute for Fiscal Studies taxpayers will be handing over an extra £2,600 a year in five years' time

Shadow chancellor George Osborne said: 'Gordon Brown has heaped stealth taxes on to hard working families and now they are feeling the squeeze.'

• Charlotte Ross: 'I classify as the "working wealthy". That's people with an average household income of £88,000 or more who still don't feel well off.'Read